Simulations of Hurricane Ike (2008) in the Gulf of Mexico Using a Coupled Ocean-atmosphere model

After Hurricane Ike (2008) passed Cuba, significant strengthening occurred from 0000 UTC 10 till 0000 UTC 13 September 2008. Ike landed in the southern Texas coast as a major hurricane. The warm water in the Gulf of Mexico (temperatures warmer than 29.5°C) associated with the Loop Current and a Loop Current eddy is believed to be the major mechanism for the intensification. In this study, a coupled ocean-atmosphere modeling system under the Earth System Modeling Framework (ESMF) using the numerical models of atmosphere (WRF) and ocean (HYCOM), is employed to examine the ocean impact on the hurricane intensity change. Hurricane initialization is conducted using WRF 3DVAR with bogus data assimilation (BDA) plus conventional data, satellite-derived cloud-track winds and QuikScat winds. With the initialization, the track prediction of Ike (2008) is similar to the observed best track, which crosses the two regions of high heat content associated with the Loop Current and a Loop Current eddy. Numerical simulations with/without ocean coupling is then compared to study the ocean impact on the hurricane's intensification. It is found that the warm ocean plays a major role in Hurricane Ike's (2008) intensification in the Gulf of Mexico. WRF 3DVAR data assimilation improves the hurricane initialization, which lays a good basis for hurricane intensity study using WRF-HYCOM modeling system.